Sensitivity analysis in multivariate methods: Decomposition of an arbitrary influence into a finite number of components

The influence function of the covariance matrix is decomposed into a finite number of components. This decomposition provides a useful tool to develop efficient methods for computing empirical influence curves related to various multivariate methods. It can also be used to characterize multivariate methods from the sensitivity perspective. A numerical example is given to demonstrate efficient computing and to characterize some procedures of exploratory factor analysis.     

Nonparametric estimation of the hazard function under dependence conditions

The estimation of the hazard rate has a great number of practical appli¬cations in dependence situations (seismicity analysis, reliability, economics), Based on kernel estimates of the density and the distribution function, we study the properties of the nonparametric estimator of the hazard function as-sociated with a strongly mixing time series. We prove consistency and asymp¬totic normality properties, and a cross-validation method for the smoothing parameter selection is studied. Some simulations and a practical application to real data are also shown.     

The Estimation and Testing of the Cointegration Order Based on the Frequency Domain

ABSTRACT

This article proposes a method to estimate the degree of cointegration in bivariate series and suggests a test statistic for testing noncointegration based on the determinant of the spectral density matrix for the frequencies close to zero. In the study, series are assumed to be I(d), 0 < d ? 1, with parameter d supposed to be known. In this context, the order of integration of the error series is I(d ? b), b ∈ [0, d]. Besides, the determinant of the spectral density matrix for the dth difference series is a power function of b. The proposed estimator for b is obtained here performing a regression of logged determinant on a set of logged Fourier frequencies. Under the null hypothesis of noncointegration, the expressions for the bias and variance of the estimator were derived and its consistency property was also obtained. The asymptotic normality of the estimator, under Gaussian and non-Gaussian innovations, was also established. A Monte Carlo study was performed and showed that the suggested test possesses correct size and good power for moderate sample sizes, when compared with other proposals in the literature. An advantage of the method proposed here, over the standard methods, is that it allows to know the order of integration of the error series without estimating a regression equation. An application was conducted to exemplify the method in a real context.     

SNA关于雇员股票期权核算方法的研究及其对中国国民经济核算的影响

本文首先综述了雇员股票期权的定义以及国际企业会计准则对雇员股票期权的处理方法.接着介绍了2008年SNA关于雇员股票期权的处理方法,并通过雇员股票期权账户登录表,更直观地展示了雇员股票期权在授权日、含权日和行权日之间,如何分别在雇主账户与雇员账户中记录.最后,对部分国家的经验数据进行了分析,并探讨了雇员股票期权作为雇员报酬处理对于中国国民经济核算,特别是收入分配核算的影响.     

On limiting behavior for arrays of rowwise negatively orthant dependent random variables

In this paper, the authors study limiting behavior for arrays of rowwise negatively orthant dependent random variables and obtain some new results which extend and improve the corresponding theorems by Hu, Móricz, and Taylor (1989), Taylor, Patterson, and Bozorgnia (2002) and Wu and Zhu (2010).     

A Bayesian Analysis of Directional Data Using the von Mises–Fisher Distribution

ABSTRACT

This article presents a Bayesian analysis of the von Mises–Fisher distribution, which is the most important distribution in the analysis of directional data. We obtain samples from the posterior distribution using a sampling-importance-resampling method. The procedure is illustrated using simulated data as well as real data sets previously analyzed in the literature.     

Language in the process of labour market rationalisation: A sociohistorical approach across twentieth-century Spain

This article analyses the role of linguistic skills in the process of defining professional classifications in Spain during 1919–1980. The aim is to determine the social evaluation of the skills involved. To retrace the classifications, a total of 114 official documents were examined, establishing a chronological division into three major stages: 1920–1940, 1940–1960 and 1960–1980. The first period (1920–1940) shows efforts toward the initial objectification of working conditions and salary scales, revealing social prejudices and tacit conventions shaping the employment hierarchy, while the second one (1940–1960) indicates the extent to which office work stood out over manual work. Finally, the third stage (1960–1980) shows processes of language rationalisation, which entailed attempts to standardise positions based on required skill sets.     

Caseworkers as a source of hope leading to perceptions of academic success for transitional age foster youth

Research among adolescent samples has consistently demonstrated that a hopeful mindset is associated with resilience and global well-being. Further, research suggests that hope is influenced from an early age from connections with supportive caregivers. However, because older youth in the child welfare system may lack supportive caregivers, alternative sources of hope may be needed. To test a theory that supportive child welfare caseworkers can serve as external sources of hope, we conducted a cross-sectional study of youth in the child welfare system from a single state (N = 149). Using surveys with established scales to measure the variables of interest, the study tested a structural equation model of (1) youth's external hope in their caseworker as a driver of (2) internal hope in themselves leading to (3) more positive perceptions of academic success. Perceptions of academic success were chosen as the final consequence of the model because academic success has been linked to many other variables of well-being across the lifespan. The results indicate that the proposed structural model fits the data well (χ² = 327.9, df = 150; P < 0.001; root-mean-square error of approximation [RMSEA] = 0.09 [90% confidence interval – CI: 0.076, 0.103]; comparative fit index [CFI]: 0.920; standardized root-mean-square residual [SRMR]: 0.05). The results indicate that youths' hope in themselves had origins in external hope in the caseworker. Moreover, the final consequence was an increase in perceptions of academic success. Such results have implications by revealing how case management services can positively influence foster youths' hope and thereby influence their academic success.     

An ant colony optimization approach for the proportionate multiprocessor open shop

Multiprocessor open shop makes a generalization to classical open shop by allowing parallel machines for the same task. Scheduling of this shop environment to minimize the makespan is a strongly NP-Hard problem. Despite its wide application areas in industry, the research in the field is still limited. In this paper, the proportionate case is considered where a task requires a fixed processing time independent of the job identity. A novel highly efficient solution representation is developed for the problem. An ant colony optimization model based on this representation is proposed with makespan minimization objective. It carries out a random exploration of the solution space and allows to search for good solution characteristics in a less time-consuming way. The algorithm performs full exploitation of search knowledge, and it successfully incorporates problem knowledge. To increase solution quality, a local exploration approach analogous to a local search, is further employed on the solution constructed. The proposed algorithm is tested over 100 benchmark instances from the literature. It outperforms the current state-of-the-art algorithm both in terms of solution quality and computational time.

     

Effective strategies for socio-educational intervention during the process of transition to adult life of unaccompanied minors from Africa

The arrival of unaccompanied minors from Africa in Spanish territory has been a constant since the last decade of the twentieth century. This migratory phenomenon has forced the child welfare system to attend to thousands of migrant children. The transition to adult life is a decisive stage in overcoming the situation of social exclusion. This research aims to analyse which socio-educational intervention strategies are effective during the process of transition to independent living with unaccompanied minors of African origin. We designed a qualitative research according to the grounded theory, which we divided into two phases. Twenty-nine young people (26 men and 3 women) participated. In phase 1, we performed two focus groups (N = 11), and in phase 2, we conducted longitudinal follow-ups (N = 18) for 24 months through 180 interviews. The results indicate the effectiveness of designing socio-educational accompaniment, prioritizing spaces of trust from which to attain the goals of emancipation. Young people consider effective those strategies that favour their knowledge of the social, labour and legal reality of the host society, designed considering each minor's individualized situation. We concluded that professional involvement acts as a buffer, reducing the bureaucratic obstacles implemented by the Spanish government.